July Temperature Update: Faustian Payment Comes Due – James Hansen and Makiko Sato

July global temperature (+1.16°C relative to 1880-1920 mean) was within a hair (0.02°C) of being the warmest July in the era of instrumental measurements (Fig. 1, left).  That’s remarkable because we are still under the influence of a fairly strong La Nina (Fig. 1, right).  Global cooling associated with La Ninas peaks five months after the La Nina peak,[1] on average.

Something is going on in addition to greenhouse warming.  The 12-month running mean global temperature (blue curve in Fig. 2) has already reached its local minimum.  Barring a large volcano that fills the stratosphere with aerosols, the blue curve should rise over the next 12 months because Earth is now far out of energy balance – more energy coming in than going out.